Can anyone tell me if the in body focus motor in the D300 is the same or comparable to the one in the D700? I'm thinking of a D300 as a back up to the D700. I have the old 80-200mm push pull and would like to mount it on the d300 and I'm just wondering if I could expect the same kinds of autofocus speeds. I'm aware that they share the multicam 3500 autofocus sensor (if there is no difference between the fx and dx ) but Im interested in if D300 has the same power or torque to turn this lump of glass at the same speed as the D700.

I'm sorry to disagree but that's not true. The screwdriver motor from the D3 is much faster than a D300's one. Actually the only thing that stays the same are the 51 points. Aquisition and locking on D3 (D4 and to a lesser degree on D700 and D800) are just amazing and nothing like the D300. In low and very low light conditions the D3 (simple, X and S) and the D4 are also stunning.

P.S. I've noticed that the posts are pretty old but other people might be interested in this too.

I ended up getting the D300 and I wouldn't notice the difference in the speed of focus between it and the D700 when the 80-200mm f2.8 af-d is mounted. The image quality, however, that's a different story Now onto the next gear lust...D800...and the only reason is that it does video.